Living Shorelines for the Vancouver Region Ideas for Restoring Coastal Habitats and Adapting to Sea Level Rise
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Living Shorelines for the Vancouver Region Ideas for restoring coastal habitats and adapting to sea level rise Prepared by Natasha Jackson-Drouin, UBC Sustainability Scholar, 2020 Prepared for Sarah Primeau, Landscape Architect & Ecologist, Space2place Design Inc. March 2021 Sustainability Scholars Disclaimer This report was produced as part of the UBC Sustainability Scholars Program, a partnership between the University of British Columbia and various local governments and organizations in support of providing graduate students with opportunities to do applied research on projects that advance sustainability across the region. This project was conducted under the mentorship of Space2place Design Inc. staff. The opinions and recommendations in this report and any errors are those of the author and do not necessarily reflect the views of Space2place Design Inc. or the University of British Columbia. Acknowledgements A big thank you to all of those who gave their time to contribute to this project and to those who shared their images included here. I want to extend a special thank you to Sarah Primeau for her guidance throughout this project. Finally, I would like to thank my feathered office mates that always had to add their two-sense. Cover art “Lo-fi” watercolor on paper by Natasha Jackson-Drouin Contents Executive Summary _________________________________________________________________ 2 Introduction _______________________________________________________________________ 4 Background _______________________________________________________________________ 4 Sea Level Rise and Coastal Habitats ___________________________________________________ 4 Living Shorelines Concept __________________________________________________________ 5 General Site Descriptions __________________________________________________________ 5 Methodology ______________________________________________________________________ 6 Literature Review _________________________________________________________________ 6 Interviews with Living Shoreline Experts _______________________________________________ 6 Design Ideas ____________________________________________________________________ 6 Research Findings __________________________________________________________________ 6 Living Shoreline Precedent Projects __________________________________________________ 6 Interviews and Meetings __________________________________________________________ 29 Sturgeon Bank: Biophysical Conditions and Selected Focal Species _________________________ 29 False Creek: Biophysical Conditions and Selected Focal Species ____________________________ 36 Design Ideas ___________________________________________________________________ 41 Conclusions ______________________________________________________________________ 45 Living Shorelines and Restoration ___________________________________________________ 45 Dynamic Systems ________________________________________________________________ 45 Other Considerations ____________________________________________________________ 45 Reciprocity _____________________________________________________________________ 46 References _______________________________________________________________________ 47 List of Figures Where required - images are used with permission Figure 1. New Brighton Salt Marsh shortly after construction (Google Earth) ____________________ 7 Figure 2. Restored salt marsh at New Brighton Park ________________________________________ 8 Figure 3. The Habitat Skirt at the Vancouver Convention Centre ______________________________ 9 Figure 4. Royston Barrier Islands at centre (Google Earth) __________________________________ 10 Figure 5. Before shoreline work done by Coastal Geologic Service at Ala spit ___________________ 11 Figure 6. After shoreline work done by Coastal Geologic Service at Ala spit _____________________ 11 Figure 7. Ala Spit (Google Earth) ______________________________________________________ 12 Figure 8. Kilisut Harbour with new bridge crossing over the restored tidal channel (Google Earth) ___ 12 Figure 9. Leque Island (Google Earth) __________________________________________________ 13 Figure 10. Underneath the cantilevered walkway at Elliott Bay ______________________________ 14 Figure 11. Marine mattresses and benches exposed at low tide at Elliott Bay Seawall _____________ 15 Figure 12. Habitat Beach next to Alaskan Way (Google Earth) _______________________________ 16 Figure 13. Seal Beach National Wildlife Refuge (Google Earth) _______________________________ 17 Figure 14. Salt marsh set inland from rip rap shoreline at Hunter’s Point South Park ______________ 18 Figure 15. Tide deck at Pier 26 below two overhanging walkways ____________________________ 19 Figure 16. Leonardtown Wharf (Google Earth) ___________________________________________ 20 Figure 17. Overview of the Floating Wetland in Baltimore Harbour ___________________________ 21 Figure 18. The Floating Wetland in Baltimore Harbour attached to two pilings __________________ 22 Figure 19. Wetland plants growing in a polyethylene/plastic matrix ___________________________ 22 Figure 20. Living shoreline breakwaters in Hancock County, MS _____________________________ 23 Figure 21. Straight on view of living shoreline breakwaters in Hancock County, MS _______________ 23 Figure 22. An example of a salt marsh cell being constructed in Heron Bay, Hancock County, MS ____ 24 Figure 23. Recycled Park in Rotterdam, Netherlands. Islands and floating wetlands (Google Earth) __ 25 Figure 24. Recycled park’s floating wetlands _____________________________________________ 25 Figure 25. Recycled park with floating wetlands and seating area ____________________________ 26 Figure 26. Carss Bush Park (Google Earth) _______________________________________________ 27 Figure 27. Living Seawall tiles installed on a seawall in Sydney, AUS ___________________________ 28 Figure 28. Closer look at the Living Seawall tiles __________________________________________ 28 Figure 29. Regional wind patterns and surface currents occurring at Iona Island _________________ 31 Figure 30. Wind data from Vancouver International Airport ________________________________ 32 Figure 31. Surface currents during tidal changes in Burrard Inlet that influence False Creek ________ 37 Figure 32. Wind data from western False Creek __________________________________________ 38 List of Tables Table 1. Summary of details - Surf Smelt and Pacific Sand Lance spawning habitats _______________ 35 Living Shorelines for the Vancouver Region | Jackson-Drouin Executive Summary This report was created as part of the Fall 2020 UBC Sustainability Scholars Program. This research project was done to inform living shoreline design options for the Vancouver region, specifically for two study areas within which Space2place Design is currently working: north Sturgeon Bank, and False Creek. A range of completed living shoreline projects were researched and selected as precedents to study further. An in-depth literature review was undertaken to identify important considerations for each study area. Interviews with experts and precedent research furthered the overall understanding of living shorelines. This culminated into a collection of examples of precedent work, context information for the sites, recommendations for focal species and a collection of design ideas that align with a living shoreline approach. The author’s working definition of a living shoreline approach is as follows: using a deeper understanding of the natural shoreline and of the natural processes that occur there, to design a more resilient and sustainable shoreline. It is moving away from a hard armoring of the shore to designing soft or green alternatives that are harmonious with the surrounding ecology and overarching coastal system. Research Findings Precedent projects (18) were selected to represent a range of built living shoreline project types. New Brighton Salt Marsh, Vancouver, B.C. Tide Deck at Pier 26, New York City, NY Vancouver Convention Centre Habitat Skirt, Leonardtown Wharf, Leonardtown, MD Vancouver, B.C. Floating Wetland, Baltimore, MD Royston Barrier Islands, Courtenay, B.C. Hancock County Living Shoreline, Hancock Ala Spit, Whidbey Island, WA County, MS Kilisut Harbour, Port Townsend, WA Deer Island, Biloxi, MS Leque Island, Stanwood, WA Recycled Park floating wetlands, Rotterdam, Elliott Bay Seawall, Seattle, WA Netherlands Elliott Bay Habitat Beach, Seattle, WA Carss Bush Park, Kogarah Bay, Sydney, Seal Beach National Wildlife Reserve, Australia Northwest Orange County, CA Living Seawall Tiles, Sydney, Australia Hunter’s Point South Park, New York City, NY Interviews and meetings (9) with living shoreline and other experts provided insight on constructed living shoreline projects and informed design ideas. 2 Living Shorelines for the Vancouver Region | Jackson-Drouin Biophysical Conditions such as tides, currents, wind, and wave conditions at each study site are included in this report. Sediment transport was a focus for Sturgeon Bank and water quality was a focus for False Creek. Conditions on the northern portion of Sturgeon Bank appear to be both erosional and accretional (Page, 2011). The main concern for water quality in False Creek is Escherichia coli concentrations. It appears that the highest concentrations of E. coli occur along the shores of the eastern portion of the inlet (Cummings, 2016). Focal Species suggestions for Sturgeon Bank are sandpipers (Western Sandpipers and Pacific Dunlin), forage fish